The invention relates to an oil separator for an internal combustion engine with a camshaft system, via which oil separator a medium comprising oil-particle-enriched blow-by gases is influenced to the effect that the oil particles and the blow-by gases are separated and supplied to an oil circuit or to an inlet system of the internal combustion engine.
A known internal combustion engine, as disclosed in DE 1 256 476, is provided with a device for venting of the crankcase and separating of the lubricating oil entrained in the venting and recycling said medium into the oil sump of the internal combustion engine. In this embodiment, a separating chamber extending substantially over the overall height of the crankcase is provided in the crankcase. The separating chamber is connected to a crank chamber via an inlet shaft which originates from the upper end of the crank chamber and opens out close above the base of the separating chamber. A sump in the separating chamber is designed as a dry sump. The latter is connected to a gear pump which has camshaft gearwheels.
U.S. Pat. No. 4,651,704 is concerned with a venting device for an internal combustion engine which has camshafts. During the operation of the internal combustion engine, blow-by medium—blow-by gases—flows/flow through an axial bore in one of the camshafts. In the process, droplet-like oil particles are separated from the blow-by gases by centrifugal forces. And, oil particles emerge through radial bores into the camshaft. The blow-by gases are supplied to the intake device of the internal combustion engine by the system pressure in the cylinder head or cylinder crankcase by means of a line.
It is an object of the invention to design an oil separator for an internal combustion engine, which can be integrated easily and in an economically advantageous manner into a camshaft system, and which furthermore is distinguished by good operation.
This and other objects are achieved according to the invention by an oil separator for an internal combustion engine via which a medium containing oil-particle-enriched blow-by gases is influenced such that oil particles and blow-by gases are separated and supplied to an oil circuit or an inlet system of the internal combustion engine, the oil separator comprising: a camshaft system of the internal combustion engine, wherein the oil particles are separated from the blow-by gases via rotation of the camshaft system; wherein the camshaft system comprises at least one camshaft on which a centrifugal blade device acting as the oil separator is effective, wherein the centrifugal blade device conveys the oil particles of the medium against housing wall portions which are adjacent relative to the camshaft and lead to the oil circuit, with the blow-by gases freed from the oil particles being conducted into the inlet system via pressure conditions prevailing in a crankcase of the internal combustion engine.
The advantages primarily achieved with the invention can be considered that of, in order to achieve the desired effect, the centrifugal blade device, which acts as oil separator, on at least one camshaft of the camshaft system accelerates the oil particles against housing wall portions extending adjacent from the latter system, from where said oil particles are conducted into the oil circuit. And, the blow-by gases freed from oil particles are conveyed in an ingenious manner by way of the pressure conditions originating from the crankcase of the internal combustion engine into the inlet system. The centrifugal blade device can ideally be realized by a blade wheel on the camshaft of the camshaft system. The latter has two parallel camshafts which are respectively provided with a blade wheel, which contributes in a manner worthy of note to optimizing the oil separating function.
Structurally and spatially advantageous conditions are achieved if the blade wheels are arranged on end regions of the camshafts. It should be emphasized in this connection that the blade wheels are provided adjacent to at least one boundary wall, wherein the latter is provided with passage openings in the region of the camshafts. For this purpose, it should also be mentioned, still with a positive effect, that the camshafts are upright and their end regions are situated close to an upper side of the internal combustion engine, with the space which is connected to the inlet system and is intended for disposing of the blow-by gases freed from oil particles being formed above the boundary wall which is provided with the passage openings. This space is closed in a simple structural way by way of a trough-shaped cover which is provided with a connecting stub for the inlet system. An expedient solution is that, on the side remote from the space, the blade wheels are fixed on the camshaft gearwheels which, for example, are mutually in engagement. As a first example, each blade wheel has a disk-shaped annular part which is provided with a receiving bore for a bearing pin portion of the camshaft and has one or more passage openings. And, as a second example, the blade wheel is held on the gearwheel of the camshaft using axially acting screws penetrating the passage openings in the annular part. This solution is supplemented by the fact that, firstly, each blade wheel comprises a multiplicity of blades which are distributed uniformly over the circumference of the annular part and extend in the axial direction toward the boundary wall, and, secondly, the axial blades have a rectangular shape.
Finally, standards are set if the annular part and the blades are produced from one piece, and if the blade wheel is composed of plastic, light metal, steel or the like, wherein the blade wheel is composed of nylon and is produced by injection molding.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.